Surgical sponge

ABSTRACT

A surgical sponge useful for delicate surgical procedures is made by providing a strip of nonwoven fibers which are securely bonded against delamination, and bonding a plastic retrieval thread to the surface of the strip by heat-softening a portion of the thread to cause it to flow partially into the surface of the strip. The resulting sponge may also have a band of radiopaque material bonded to its surface by heat-softening the plastic material of the band.

United States Patent Reimels 1 1 June 5, 1973 [541 SURGICAL SPONGE3,431,909 3/1969 Krusko "128/285 3,464,415 9/1969 Brownlee ..l28/296Inventor Harry Bramrec Mass 3,520,302 7/1970 Jones 1 1 ..l28/285 I73]Assignee: Codman 8r Shurtleff, lnc., Rudolph, 3,610,245 I0/l97lBernardin ..|28/290 W Mass.

Primary Examiner-Charles F. Rosenbaum [22] Filed I971 Attorney-James R.Hulen and Robert L. Minier [2l] Appl.N0.: 116,187

[57] ABSTRACT [52] U.S. Cl. ..l28/296 A surgical sponge useful fordelicate surgical [5]] Int. Cl. ..A6lf 13/00 procedures is made byproviding a strip of nonwoven [58] Field of Search ..l28/285, 296 fiberswhich are securely bonded against delamination, and bonding a plasticretrieval thread to the sur- [56] Refe ce Cited face of the strip byheat-softening a portion of the UNITED STATES PATENTS Bletzinger et al 128/285 X Deker 128/296 Hirsch ct al. 128/296 Rowan ..l 28/296 X threadto cause it to flow partially into the surface of the strip. Theresulting sponge may also have a band of radiopaque material bonded toits surface by heatsoftening the plastic material of the band.

4 Claims, 5 Drawing Figures SURGICAL SPONGE BACKGROUND OF THE INVENTIONThis invention relates to surgical sponges and, more particularly, tosurgical sponges suitable for use in laminectomies, craniotomies, nervesurgery or other delicate surgical procedures.

It has been the practice in the above types of surgery to utilize arelatively small, thin strip of bonded nonwoven fibers as a sponge. Thistype of miniature sponge is necessary because of the small operatingfield and the delicate nature of the procedure. However, because of itssize, it is necessary to attach some means, such as, a retrieval thread,to the sponges in order to insure that the sponges will not be left inthe wound and to provide a handle for applying and withdrawing thesponges from the wound site.

Prior surgical sponges of this type utilized retrieval threads that werestitched directly to one or both surfaces of the sponge and often, whendesired, a strip of radiopaque material was combined with the thread andsimultaneously stitched to the sponge. When fabricated in this manner,the sponges were rough on both sides, in that the stitching extendedentirely through the sponge. Also, the combination of retrieval threadand radiopaque material was unsafe because the accidental release of oneelement would result in the release of the other element, thus,rendering the sponge free of detection means and capable of beinginadvertently left in the wound.

In addition, the stitching operation utilized to fabricate the spongeswas necessarily a hand operation resulting in an excessively largemanufacturing cost.

SUMMARY OF THE INVENTION The disadvantages of the prior surgical spongesare eliminated by the present invention which provides a unique spongeconstruction comprising a strip of nonwoven bonded fibers having aplastic retrieval thread secured to one surface thereof solely by aflattened portion of the thread that has been heat-softened to flowpartially into and between the fibers of the strip.

One or more bands of radiopaque material may also be bonded to thesurface of the sponge in the same manner and at the same time, but at adifferent location, as the plastic retrieval thread.

The various elements of the sponge may be simultaneously fabricated byproperly positioning the strip, plastic retrieval thread and radiopaquebands under the horn of an ultrasonic welding device and then bringingthe horn into contact with the thread and bands.

Thus, in a single manipulative step, an improved surgical sponge may befabricated which possesses numerous advantages over all known priorsponges.

For a better understanding of the invention, as well as other objectsand further features thereof, reference is made to the followingdetailed description to be read in conjunction with the accompanyingdrawings, wherein:

FIG. 1 is a plan view of the surgical sponge of the present inventionwith portions broken away for clarity;

FIG. 2 is a cross sectional view taken along line 22 in FIG. 1;

FIG. 3 is a side elevational view schematically illustrating the processfor manufacturing the surgical sponge shown in FIG. 1;

FIG. 4 is a cross sectional view taken along line 44 in FIG. 3; and

FIG. 5 is a plan view of another embodiment of the surgical sponge withparts broken away for clarity.

Referring to FIGS. 1 and 2, the preferred embodiment of the surgicalsponge of this invention is shown generally at 10 and is constructedfrom a relatively thin strip of nonwoven fibers 11 which have beensecurely bonded together to prevent delamination or linting of thefibers. Strip 11 is preferably constructed from rayon fibers which havebeen carded in a well known manner and then needle loomed into sheets,which sheets are then cut into strips of the desired length and width.The rayon fibers are preferably a dull, virgin, 3 denier rayon with anominal staple length of approximately 1% inches. This type of materialhas been manufactured and used for surgical sponges in the past and ithas been found that, when bonded with a mixture of starch and polyvinylalcohol, the strips will retain their integrity and the material hasbeen tested and found to absorb in excess of 25 times its weight inwater.

A retrieval thread 12 is bonded to one surface of strip 1 l andcomprises a flattened portion 13 which has been heat-softened to providea secure bond between thread 12 and the surface of strip 11. As stated,above, surgical sponge 10 is primarily intended for use in very delicatesurgical procedures and the operating field is considerably smaller inthis type of operation than is normally found in more massive surgery.For this reason, the relatively small, thin sponges are used and a meansmust be provided in association with these sponges for retrieving themafter they have been applied to a wound site and have absorbed aconsiderable amount of body fluid. Retrieval thread 12 has been providedfor this purpose and the bond between the thread and the surface ofstrip 11 is, therefore, very important. The length of thread 12 is notcritical so long as it can be placed at a sufficient distance outsidethe wound to be recognizable and easily handled by the surgeon and hisassistants.

Retrieval thread 12 is preferably made from a continuous multifilamentpolyester fiber. However, it has been found that other plasticmaterials, such as, nylon and polypropylene will also provide a securebond. However, the polyester material results in the best combination ofend product properties, such as, strength of bond and softness of thethread.

In addition to retrieval thread 12, a pair of bands 14 and 15 composedof radiopaque material is also securely bonded to the surface of strip11. Although two bands of radiopaque material are illustrated in thepreferred embodiment of this invention, it will be appreciated that onlyone band may be desirable for exceptionally small surgical sponges andtwo or more may be utilized in larger sponges. Although numerousradiopaque materials may be usable with this invention it has been foundthat vinyl with barium sulfate dispersed therein is very effective andforms a very secure bond with the surface of strip 11.

The preferred method for manufacturing the surgical sponge of thepresent invention is an important part of the invention and will now bedescribed in detail. Referring to FIG. 3, the procedure forheat-softening the retrieval thread 12 and the radiopaque bands 14 and15 is schematically illustrated. In order to avoid the necessity ofutilizing additional materials, such as, adhesives, and in order toeliminate the deleterious effects of the application of heat to obtainthe necessary bond between the retrieval thread 12, bands 14 and 15 andthe surface of strip 11, an ultrasonic welding device has been adopted.This device is specifically described in US. Pat. No. 3,440,117 andcomprises a radio frequency generator 20, a conductor 21 fortransmitting alternating current energy at about 20 kilocycles persecond from the generator 20 to a sonic converter unit 22. Sonicconverter 22 is fitted with a horn 23 for transferring sonic energy tothe thread 12 and bands 14 and 15. The sonic converter 22, generally, isa device which converts electrical energy to mechanical vibration and,to this end, includes one or more piezoelectric discs which vibrateunder the influence of alternating current in electrical energy. Thevibrations are amplified and appear as longitudinal vibration at the tipof horn 23.

In order to accomplish the simultaneous assembly of all of the elementsof the surgical sponge l0, strip 11 is placed upon a' support member 24which is located directly below ultrasonic welding horn 23. Retrievalthread 12 and bands 14 and 15 are then placed upon strip 11substantially as shown in FIG. 1. Referring to FIG. 4, the lower portionof horn 23 has been specially constructed so that a plurality of ribs 25extend downwardly therefrom. Ribs 25 are constructed to contact only somuch of the material of retrieval thread 12 and bands 14 and 15 as isnecessary to sufficiently heatsoften the materials so that they willflow into the upper surface of strip 11 and form a secure bond betweenthe material and the fibers that comprise the surface. As can be seen inFIG. 2, the action of horn 23 on the upper surfaces of thread 12 andbands 14 and 15 substantially flattens these materials and forces theminto the upper surface of strip 11 and firmly bonds them to saidsurface.

In some instances, e.g. where a more flexible surgical sponge isdesired, it has been found to be desirable to reduce the area of thebonding interface between strip 11 and retrieval thread 12. Thepreferred sponge construction for accomplishing this is illustrated inFIG. wherein the sponge a comprises a strip 11a having a retrievalthread 12a bonded to the surface thereof. However, unlike the sponge inFIG. 1, the bond occurs only at spaced intervals B along the length ofpartially flattened portion 13a on thread 120. The unbonded areas act ashinges" and, thus, provide regions of increased flexibility.

In order to provide this type of bond, ribs 25 on the lower portion ofhorn 23 (see FIG. 4) may be longitudinally notched so that contact ismade between horn 23 and retrieval thread 12a only at the predeterminedspaced intervals, thus, creating a bond at only such intervals.

It will thus be apparent that the present invention provides a uniquesurgical sponge construction that has many advantages over the priorknown sponges. By eliminating the need for stitching or utilizingadhesives, a surgical sponge can now be constructed that is completelysmooth on one side for application to the wound site. In addition, theradiopaque bands may now be applied at a location different from that ofthe retrieval thread and thereby provide additional safety in the eventthat the retrieval thread is accidentally pulled away from the surfaceof the strip. It will also be apparent from the foregoing specificationthat the method of manufacturing the surgical sponge of this inventionis extremely economical in that all of the parts may be assembled in oneoperation and no additional materials, such as, adhesives are requiredin the assembly of the parts.

What is claimed is:

l. A surgical sponge useful for delicate procedures comprising: asubstantially flat strip of securely bonded nonwoven fibers; a plasticretrieval thread bonded to only one surface of said strip, said bondbeing achieved solely by a flattened portion of said thread that isinterlocked with the surface fibers of said strip; and a band ofradiopaque material bonded to the surface of said strip at a locationdifferent from said thread.

2. The sponge of claim 1 wherein the bond between said radiopaquematerial and said strip is achieved solely by the interlocking contactbetween said mate'- rial and the surface fibers of said strip.

3. The sponge of claim 2 wherein said nonwoven fibers are rayon, saidplastic retrieval thread is a continuous multi-filament polyester andsaid radiopaque material is vinyl containing barium sulfate.

4. A surgical sponge useful for delicate procedures comprising: asubstantially flat strip of securely bonded nonwoven rayon fibers; and acontinuous multifilament polyester retrieval thread bonded to only onesurface of said strip, said bond being achieved solely by a flattenedportion of said thread that is interlocked with the surface fibers ofsaid strip.

1. A surgical sponge useful for delicate procedures comprising: asubstantially flat strip of securely bonded nonwoven fibers; a plasticretrieval thread bonded to only one surface of said strip, said bondbeing achieved solely by a flattened portion of said thread that isinterlocked with the surface fibers of said strip; and a band ofradiopaque material bonded to the surface of said strip at a locationdifferent from said thread.
 2. ThE sponge of claim 1 wherein the bondbetween said radiopaque material and said strip is achieved solely bythe interlocking contact between said material and the surface fibers ofsaid strip.
 3. The sponge of claim 2 wherein said nonwoven fibers arerayon, said plastic retrieval thread is a continuous multi-filamentpolyester and said radiopaque material is vinyl containing bariumsulfate.
 4. A surgical sponge useful for delicate procedures comprising:a substantially flat strip of securely bonded nonwoven rayon fibers; anda continuous multifilament polyester retrieval thread bonded to only onesurface of said strip, said bond being achieved solely by a flattenedportion of said thread that is interlocked with the surface fibers ofsaid strip.